SVX Engine cooling "Again & Again" - Page 58

Trevor · #**856** 01-20-2010, 05:07 PM

Quote:

Originally Posted by oab_au

This thread has 799 posts, Tony has 254, Trevor has 134, Bill 66, I have 47.

If you read Trevor's posts here, you will not find a lot of constructive help on this thread. If the thread is to be made readable, these 134 posts could be removed, and the thread would not lose any content.

Harvey.

Harvey, your last and current, completely superfluous, unintelligible post, clearly illustrates the stupidity of your nasty remarks as above. In accordance with your previous glibly recorded statement, your post should be removed.

Dessertrunner · #**857** 01-20-2010, 06:28 PM

Start the test but car did have much power, have had a problem for the last day, running rough. Then it was:-

"Huston we have a problem"

Then got a tow home to find this, its the first time in my life it has let me down.
Tony

SVXRide · #**858** 01-20-2010, 07:12 PM

Tony,
Sorry, but I can't tell from that picture what the problem is

Timing belt looks fine, idlers are where they're supposed to be, radiator has obviously been removed and there's coolant on the floor...
-Bill

Dessertrunner · #**859** 01-20-2010, 07:36 PM

Most of the teeth are missing from the belt. It stripped the timiming belt

SVXRide · #**860** 01-20-2010, 08:04 PM

Quote:

Originally Posted by Dessertrunner

Most of the teeth are missing from the belt. It stripped the timiming belt

Tony,
Ah, now I can see! Okay, so what froze up to cause the teeth to get stripped off, or is the belt just really, really old and dried out from all that time in the Outback heat?

-Bill

SilverSpear · #**861** 01-20-2010, 11:46 PM

Quote:

Originally Posted by SVXRide

Tony,
Ah, now I can see! Okay, so what froze up to cause the teeth to get stripped off, or is the belt just really, really old and dried out from all that time in the Outback heat?

-Bill

Yeah this is weird. We are curious to know...

Dessertrunner · #**862** 01-21-2010, 01:04 AM

First off have fixed it. Belt had 90,000 on it so it should have lasted longer, it was a after market so i think it was not up to the job. Also the cover had a hole in it just behind harmonic balancer that let a bit of sand in. Thats about all I know.

Back to cooling did a quick run after fixing the car. Outside temp was 38C did the different gear and same speed as I did before. If you remember last time I had to cancel the trial as the car was going to boil. This time I could not get the engine temp to go over 100. When I was crusine and the temps were 70 radiator 90 engine this was 6th gear. In the lowest gear possiable (3rd) I could have driven that way all day that's at 5,750 rpm. The only change was radiator went to 80 engine 100. Its clear that the problem of cooling at higher rev has been imorived if not fixed.
I did give the car a hard time to see what would happen but it didn't bother it anymore so it seems like we are heading in the right direction. Its worth me mentioning that from a cooling point of view I though I was in a different car.
Have a great day.
Tony

SilverSpear · #**863** 01-21-2010, 01:15 AM

Thank you for your feedback Tony, glad the issue has been resolved.

Dessertrunner · #**864** 01-21-2010, 02:16 AM

Quote:

Originally Posted by Dessertrunner

Did a test on the way to get some parts. The results are pretty interesting
Target of test was drive constant speed just different revs by changing gear down. In third at 5,500 rpm had to cancel the trial as the car would have cooked as the engine failed to cool. In theory the load was constant the only change was the revs. Haven't had time to graph but will at some point.
Air Temp 30C
6th gear 2,600 rpm return coolent temp 63C engine temp 95C
5th 3,750 80C 97C
4th 4,100 85C 100C
3rd 5,500 92C climbing 105C Stopped trial.

Drove 30 k same speed in 6th and temps return to previous result.
Tony

Today's test was at an air temp of 38C so I think its safe to say I have proved the point about the pump suction.
Tony

SVXRide · #**865** 01-21-2010, 08:16 AM

Tony,

Outstanding! Bravo!

So, just to make sure we're all on the same page (given that this thread has many, many pages

), your car is currently configured as follows:

1. PWR radiator with stock cap, stock inlet, and 45mm ID outlet relocated to the center of the bottom of the radiator,
2. Water pump inlet modified to 45mm ID,
3. Modified stock cross over pipe

Question - were you running a 'stat in the current set up that resulted in the stated temperatures?

Thanks again for all your hard work!
-Bill
p.s. have you considered machining up a couple of the modified water pump inlets and offering them to those not fortunate enough to have full 6 axis mills available?

Dessertrunner · #**866** 01-21-2010, 01:10 PM

Bill,
Not sure what will happen when we run the state but will do a trail and its yes to the rest of the questions.
I am looking at the final cover design I think it will be a lot simpler but yes we could see what we can do.

Okay redid the test at 30c air temp.
6th gear 58 radiator return 72 engine
4th 62 78
3rd 70 88

I think its fair to say the proof is in the numbers, there was no change of the engine overheating. The improvment to the cooling is mind blowing.
Tony

Nomake Wan · #**867** 01-21-2010, 04:20 PM

I've been following this thread with much interest, since I remember way back when I had an SVX the problems that racers were having with the motors overheating and blowing coolant. I can't believe that the fix is something as simple as enlarging the radiator outlet and pump inlet, but you can't argue with cold hard results. Still... you'd think Subaru's engineers would have been able to figure something like this out back when the car was in development.

Bravo, Tony. Well done.

Dessertrunner · #**868** 01-21-2010, 06:07 PM

Subaru fell for the same trap as Trevor, they beleived that a closed loop system ment that some of the pressure would turn up at the pump inlet. This is fundemtally incorrect. If I take the outlet from the pump and infeed it into the inlet unless there is a restriction in the system there will be no pressure on the outlet of the pump and unless there is a restriction close to the inlet there will be no vacum. The water loops for the minium pumping energy.
On the other hand if I either block off the suction or the outlet the whole pressure?vacum numbers changes. It would be possiable to restrict the suction so as the pump is pumping vacum but the outlet is reading zero pressure.
The way it works is the restriction in the system can be large enough to increase pressure but still small enough to not cuase a problem on the suction. If the restriction gets to great the suction goes up till the pump drops off which then gives the impression that the pressure is not a problem.
Sorry about the long explantion.
As regards Subaru, I had a problem with John Deere Engines a couple of years back were they kept shutting down for no reason and John Deere were ripping there hair out trying to sort find the problem. I figured out that it was a conflict in the computer system and I cut one wir then they never stopped again. Big companies aren't always right they just think they are. Have a great day.
Tony

Trevor · #**869** 01-21-2010, 06:40 PM

Quote:

Originally Posted by Dessertrunner

Today's test was at an air temp of 38C so I think its safe to say I have proved the point about the pump suction.
Tony

Tony,

It is understood that your test Oct 2009, ref. post #249, is the basis of comparison, i.e. as per post #864. It would appear that you started out with a radiator, having an inlet and outlet pipe with an OD of 30 mm. Refer your post Page 4, No. #48. Was this radiator in use during the October 2009 testing?

My JDM SVX has an original radiator which has 38 mm, or 1,1/2 inches OD, inlet and outlet pipes. It would therefore appear that your original radiator was not to manufacturers specifications. All is confusion, particularly as many figures within the thread, have been quoted without any refernce to OD or ID.

In any event it would appear that this previous test was carried out with a radiator different from what you are now using. If so, several changes have now been involved, in addition to the enlarged radiator outlet and pump inlet.

In all of this, one thing is scientifically certain. Whatever goes into the radiator via a hole, the same can exit unrestricted via a similar sized hole. Several explanations have ignored this simple fact.

TomsSVX · #**870** 01-21-2010, 06:54 PM

Im with trevor here, whatever enters the radiator at 1.5" OD can and should exit at the same diameter... Rather than just trying to make a bigger opening to come out of the radiator would it not be just as plausible to have a custom hose made to expand from 1.5 out of the the 1.75 require inlet to the pump?

Are you using a thermostat???????????

Tom